* New pix icon i/externallink
* New lang string opensinnewwindow
* Use the external link pix icon with "Opens in new window" lang string
as its alt text and add it to the "Give feedback about this software"
link.
* Update cta template to indicate whether the link opens in new window.
Some browsers like Firefox are very inflexible with window.open()
and block it if it is not instantly invoked after the user click.
Also according to https://stackoverflow.com/a/6807615 it is best
practice to replace self:: with static::
Fetching the theme version number via get_component_version() which
requires lib/adminlib.php unnecessarily increases memory consumption.
Using get_config() is more direct and simpler.
